Method for operating a long stator linear motor with switch

Abstract

To safely avoid a collision of two transport units in the switch area during operation of a conveyor in the form of a long stator linear motor with a switch, a collision zone is provided in the switch area, wherein the collision zone extends from the beginning of the switch in each case a length on the respective conveyor section, and to define the collision zone, the transport units are considered as two-dimensional objects and a position of the first transport unit on the first conveyor section is determined, which the first transport unit is allowed to occupy, so that the second transport unit can be moved as a two-dimensional object along the second conveyor section without collision through the switch and a distance between this first position and the beginning of the switch is determined and at least this distance is used as the first length.

The invention claimed is: 
     
       1. Method for operating a conveyor in the form of a long stator linear motor having a conveying path with at least one switch, with which a first conveyor section of the conveyor path is connected to a second conveyor section of the conveyor path and the first conveyor section and the second conveyor section diverge from a beginning of a switch in a region of the switch, the method comprising:
 along the conveying path, a first transport unit and a second transport unit are moved and, to avoid collisions between the first transport unit and the second transport unit, a collision zone is set in the region of the switch, in which there is a risk of collision between the first transport unit and the second transport unit, 
 wherein the collision zone extends from the beginning of the switch with a first length to a first end at the first conveyor section and extends from the beginning of the switch with a second length to a second end at the second conveyor section; 
 modeling the first transport unit on the first conveyor section and the second transport unit on the second conveyor section as two-dimensional objects; 
 at least one of selecting a two-dimensional geometric shape as a two-dimensional object for the first transport unit which surrounds a contour of the first transport unit or selecting a two-dimensional shape as a two-dimensional object for the second transport unit which surrounds a contour of the second transport unit; 
 with at least a part of the two-dimensional object modelling the first transport unit, determining a first position on the first conveyor section occupiable by the first transport unit, so that the second transport unit modeled as a two-dimensional object is movable along the second conveyor section collision-free through the switch; and 
 determining a distance between the first position and the beginning of the switch, which is used as the first length. 
 
     
     
       2. The method according to  claim 1 , further comprising:
 determining a second position of the second transport unit as a two-dimensional object on the second conveyor section that the second transport unit is allowed to occupy, so that the first transport unit as a two-dimensional object is movable along the first conveyor section collision-free through the switch; and 
 determining a distance between the second position and the beginning of the switch, which is used as the second length. 
 
     
     
       3. The method according to  claim 1 , wherein the second length is set equal to the first length. 
     
     
       4. The method according to  claim 1 , wherein at least one of the first transport unit with a part conveyed by it or the second transport unit with part conveyed by it are modeled as two-dimensional objects. 
     
     
       5. The method according to  claim 1 , wherein, for different combinations of different first and second transport units, different collision zones are set for a switch. 
     
     
       6. The method according to  claim 1 , wherein for different switches, different collision zones are defined. 
     
     
       7. The method according to  claim 1 , wherein a second transport unit is allowed access to the collision zone on the second conveyor section in which the first transport unit is located, when a collision-free movement of the second transport unit into the collision zone is possible or a first transport unit is allowed access to the collision zone, in which the second transport unit is located, when collision-free movement of the first transport unit into the collision zone is possible. 
     
     
       8. The method according to  claim 7 , wherein a minimum distance between the first transport unit and the second transport unit is set, which must be complied with so that the first transport unit and the second transport unit are movable collision-free through the switch, and
 wherein to check compliance with the minimum distance, at least one of the first transport unit on the first conveyor section in the collision zone is projected onto the second conveyor section in the collision zone or the second transport unit on the second conveyor section the collision zone is projected onto the first conveyor section in the collision zone. 
 
     
     
       9. The method according to  claim 8 , wherein the minimum distance is determined at least one of depending on a geometry of the first or second conveyor section in the region of the switch or depending on a geometry of the switch. 
     
     
       10. The method according to  claim 8 , wherein, for different combinations of different first and second transport units, different minimum distances are set. 
     
     
       11. The method according to  claim 1 , wherein the beginning of the switch is a point at which the first conveyor section begins to diverge from the second conveyor section.